It seems to be a tricky issue, not just up here too. Generalised guidelines for RA protection do not seem to exist. I know what you mean, I worry/wonder sometimes too. I've yet to get a convincing answer on way or another regarding lichen. I've not been, but I hear Chatton has a hoof problem. I guess each panel must be considered on it's own merits.

The turf at Millstone sounds a bit shan too. I've indulged in peel and reveal myself, but it's always 'peel-reveal-replace', permanent removal of turf is not nice.

If you ever want to hear a right old rant, send me your mail addy, and I'll go on and on about the stone at Throckley. For ages. On and on and on.

Like the look of those elephantine formations btw.